Installed the 1zz throttle body -

[AlexNet0]

Originally Posted by MGargano

Anyone have any success with this?

Not that I know of, swapping the TB chips is what is helping other people

[jkuchta]

Originally Posted by AlexNet0

Not that I know of, swapping the TB chips is what is helping other people

Yes...this swap works!

http://www.yarisworld.com/forums/sho...5&postcount=78

[white_rice]

Sorry to bring an old thread back to life but I did a search for a CEL code and it brought up this thread.

Purchased a 1zz throttle body off a member here about a month ago. This is the one here, which is the correct one to use as per the forums:

http://www.yarisworld.com/forums/showthread.php?t=51570

So anyways took the car to my mechanic friends shop tonight to do the install. Firs thing we did was disconnect the battery. Removed the existing throttle body.

Quickly realized that the rubber coupler from my K&N Typhoon short ram intake would not fit over the new larger diameter of the 1zz TB. Luckily he had an OEM air box and tubing from a Civic in his shop. Fit perfectly over the 1zz so we cut that down to size and had our new coupler.

Also then realized that the O-ring seal was too small and wouldn't make a proper seal. He had some gasket maker (Permatex Ultra Black) on hand so we put a nice thick coat of that on the throttle body to ensure no air leaks.

Had to put on some different hose clamps as well for the new thicker coupler as existing ones were too small now.

Put everything back together. Re-connected the battery. First turn of the key it did not fire. Very sluggish. Tried again and it fired up but with a very high, fluctuating idle. Let it sit and run and after about 60 seconds or so, idle began to drop and drop until it eventually got to where it should be. We let the car run at idle for 10 minutes before shutting off engine.

He then used a stethoscope to ensure no vacuum leaks as he was concerned about the high revving upon starting. No leaks detected.

We then took it for a test drive down the road. Felt very nice. Definitely more responsive.

It wasn't until we got back to his shop 5 minutes later that we realized we now had a CEL. He used his Scanguage and read the code. Not 100% sure of code but from researching on forum, it must have been P0505. As the code error read as 'Idle Control System Malfunction'.

Cleared the code, and re-started the car and it went away. Shut off and on and again and code did not come back. Figured it just had come on due to the very high revving on initial start.

It wasn't until about 15 minutes after I was driving home that the CEL popped back on again!

On that note -- thats why I'm posting asking for advice. I did some reading. 2 things that have come to my attention are breaking up the epoxy on that allan key idle screw and adjusting. I also read about swapping some sensor or chip. I'm confused as to what chip exactly. One from the existing OEM TB and onto the new 1zz TB? Do you believe that either of these 2 might be the issue, throwing me a CEL? Also, never did this colont bypass people are talking about either, as I live in a cold climate (Southern Ontario, Canada).

Please give any advice to help me rid of the CEL.

------

So I've spent the last 2+ hours reading through more threads. It appears that nobody knows the 'definite' cause for this CEL, however it is sometime remedied by either adjusting that idle screw, or swapping the sensors from the one on the OEM TB. We can attempt these when I had back to my mechanics. My only other concern is that we did drive the car not too long after we installed the gasket sealer. Hoping that isn't an issue with it getting sucked into the intake manifold. He did say its a very fast drying sealer. I'm pretty convinced it might be that idle screw needing adjusting. Will have to post progress. Not heading back there for a couple weeks though so have patience. :)

[tk-421]

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

[white_rice]

Originally Posted by tk-421

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

Thank you. So you just swapped the chip, but didn't touch that idle screw at all?

[tk-421]

My TB came with a big gunk of epoxy on the idle screw, so I just left it as is. I suspect this is what causes a high idle on the first ~30 secs of starting up, but I'm pretty sure that has nothing to do with your CEL.
Then again, tweaking that screw might just do the trick...

[white_rice]

Originally Posted by tk-421

My TB came with a big gunk of epoxy on the idle screw, so I just left it as is. I suspect this is what causes a high idle on the first ~30 secs of starting up, but I'm pretty sure that has nothing to do with your CEL.
Then again, tweaking that screw might just do the trick...

Yeah thats what I'm confused of. Nobody ever seem to have come up with a definite answer as to which one (if either) of these problems was the definite issue causing the CEL. Seems to be more of a hit or miss fix to the problem. Some people appear to have never got the CEL at all. Too many variables here. Suppose I will start with the chip swap and move along from there.

[white_rice]

Originally Posted by tk-421

I did the chip swap by keeping the OEM chip and ditching the 1ZZ chip. Took 5 minutes to remove the rivets using a drill with a small bit and another 5 minutes to screw everything back up. Have yet to encounter a CEL due to this.

Also what size screws did you use to replace the existing rivets?

[tk-421]

Originally Posted by white_rice

Too many variables here. Suppose I will start with the chip swap and move along from there.

The chip swap should be enough to fix it. I'm 99% sure the idle screw just helps nudge the idle up or down in the RPM range, but not enough to throw a CEL.
Just make sure the battery has been disconnected for a while. Otherwise you won't be able to tell for sure if it's due to the ECU storing previous settings or not.

Originally Posted by white_rice

Also what size screws did you use to replace the existing rivets?

Dang it! I knew you were gonna ask that...
Unfortunately I can't tell for sure. I just looked around for some screws and I found the perfect set with nuts to match.

[Rigaud]

I did not disconnect the battery, left it live. Swapped chips and removed the epoxy to dial the idle but only while it wasn't running. The P0505 is due to high idle and the oscillation the ECU searching and needs to learn. I had the oscillation too at first, it went away after a day or two. I had the P0505 popping up every day for two weeks but it took longer every time for it to show up. Eventually all has settled itself and works great. Best direct upgrade I did so far. My installation went fairly well because I did some reading on hear first before doing the job and not after the fact. ;)

Give it some time for your ECU to relearn with the bigger TB.